The tiniest, most complicated set of instructions just got a little easier to read, thanks to a giant scientific project called ENCODE, which recruited more than 400 scientists from all over the world.

Those instructions reside in a long molecule called DNA. And one copy of this DNA resides within almost every cell, telling it how to operate.

Without DNA, life would be impossible. Trees have DNA; so do animals, mushrooms, bacteria, and people. Previous studies of human DNA determined the function of only a fraction of the molecule. The global team has been trying to understand what, if anything, the rest of that DNA might do.

ENCODE turned up evidence that the majority of the DNA molecule contains segments that may turn other portions “on” or “off.” Some segments may also control how DNA gets folded up.